The Mansfield 07 11.5" Ballcock Anti-Siphon is a plumbing fixture made of copper and bronze. It is designed to prevent backflow and maintain water levels in a toilet tank. This particular product is new old stock (NOS), meaning it has never been used before and is in original condition. The Mansfield brand is known for producing high-quality plumbing products, making this ballcock a reliable choice for maintaining your toilet's water supply.